1. Field of the Invention
This invention relates to an instrument probe assembly and, in particular, to an improved sealed probe assembly.
2. Brief Statement of the Prior Art
Instrument probe assemblies are commonly employed for capacitance measurement of levels of liquids or granular solids in process vessels comprise an elongated probe member received within, and electrically isolated from, an assembly body. The assembly body has attachment means, typically an end gland bearing conventional pipe threads to permit its insertion into an aperture of a process vessel with the elongted probe member projecting therefrom into the interior of the vessel. The probe assemblies are often employed in pressure vessels and the superatmospheric pressure encountered can cause the process fluids to invade the cavity of the assembly body, destroying the electrical insulation between the probe and body and requiring servicing of the assembly.